Method of treating hosiery fabric



United States Patent 3,135,578 METHOD OF TREATlNG HGSIERY FABRHC Palmer G. Hendrix and Hoke D. Whisnant, Hickory, N.C., assignors to Whisnant Hosiery Mills, Inc., Hickory, N.C., a corporation of North Carolina No Drawing. Filed Mar. 5, 1962, Ser. No. 177,185 "2 Claims. (Cl. 8-116) This invention relates to a process for rendering clothing fabric in a manner such that the fabric will afford a greater cooling effect when worn adjacent the human skin than the cooling effect of similar fabric which has not been so rendered. More particularly this invention relates to a process for treating mercerized or numercerized cotton fabric so as to render said fabric capable of transmitting heat through and away from the fabric more readily than such fabric which has not been so treated.

The discomfort of the human body when clothed and subject to high temperatures and humidity is well known. Attempts to alleviate such discomfort have included the development of lighter clothes and clothes having ventilating characteristics. However, obvious limitations prevent the utilization of greater improvements of this type to increase comfort. It is an object of this invention to increase the comfort of the clothed human body by increasing the heat transfer rate of the clothing worn adjacent the skin, such as socks, undergarments and the like.

It is another object of this invention to provide such an increased heat transfer rate only upon the onset of discomfort evidenced by perspiration.

It is another object of this invention to provide clothing having such capacity for increased heat transfer without substantially increasing the cost of manufacture of such clothing.

It has now been discovered that mercerized or unmercerized cotton fabric, either knit or woven, and in the raw or finished article form, may, by the process of this invention, be treated so as to increase the heat transfer rate thereof in the moist state. In this manner, when such fabric, in the form of socks, undergarments, etc., is worn adjacent the human skin, an amount of discomfort which induces perspiration, will be alleviated as the perspiration moistens the treated fabric, since the increased heat transfer rate through the fabric will impart a cooling sensation to the body, and retard the rate of rise in the ambient temperature at the skin.

In accordance with the principles of this invention, to a water bath is added a caustic alkali in an amount in the range of from about .25 to about 10% by weight of the cotton goods to be treated. After this alkali addition and dispersal thereof throughout the water bath, the pH of the bath is adjusted to within the range of from about pH 5.8 to about pH 7 by the addition of acetic acid. Caution should be exercised to prevent the end point of this pH adjustment from falling substantially below pH 5.8, since a lower pH will impart an acid odor to the goods and may render the goods allergenic to the skin. The preferred pH in accordance with the principles of our invention is about pH 5.8. The cotton goods to be treated are then immersed in the bath, and preferably agitated during the remainder of the processing. At this point conventional finishing agents may be added to the water bath such as cationic softeners, and bactericidal agents such as certain organic metal oxides and the like. Similarly, a wetting agent may be added as a dispersant, but such addition is not critical. However, the use of finishing agents such as emulsified polyethylenes, resinous products and the like, which would seal the fibrous structure of the cotton fabric must be avoided in lice order that the cooling effect produced by the process of this invention be ensured. Following the discretionary addition of these conventional agents, the Water bath so constituted is agitated until the cotton goods have taken up liquid from the bath in an amount in the range of from about 10% to about 60% by weight of the dry weight of the goods being treated. During this liquid takeup, the temperature of the bath is preferably maintained at a temperature of about F.

As soon as the cotton goods have taken up the desired amount of bath liquid, they are removed from the bath and dried by any conventional means. After drying, the finished goods treated in accordance with the process of this invention are ready for wear, while the unfabricated goods are made into the desired clothing articles. The cotton clothing when worn has a distinct cooling effect greater than that exhibited when untreated cotton clothing is worn adjacent the skin. In order to measure the amount of this cooling effect, treated and untreated cotton socks were tested in accordance with the following examples.

Example I A dyetub is filled with water. 0.075 pound of sodium hydroxide is then added to the water and allowed to disperse thoroughly with agitation. 0.05 pound of glacial acetic acid is then added, whereupon the pH of the bath reads 7. Ten pounds of cotton stockings are then immersed in the bath and agitated constantly for 20 minutes. During this agitation the temperature of the bath is maintained at 100 F. The stockings are then removed and boarded.

Example II A polyurethane plastic bottle of 500 cc. capacity was filled with water and the temperature sensitive element of a Simpson Model 389 thermometer was inserted through a rubber stopper in the mouth of the bottle so as to be surrounded by the water. A cotton sock, treated in accordance With the process of Example I was dampened with water and stretched over the surface of the 500 cc. bottle, encasing the bottle as a sock would a foot. A similarly water-filled and instrumented bottle was encased with a dampened untreated sock having the same construction as the treated sock. Both sock-encased bottles were then supported in the path of air flowing from a Knapp-Monarch tin-radiated electric heater. The temperature of the air at a point adjacent each bottle was maintained at F. during the test. Timing was begun and the temperature of the water inside of each bottle was tabulated as follows:

Temperature, F.

Time

Bottle 1- Bottle 2- Treated Untreated Sock Sock Example III In accordance with the procedure of Example II, the

1 ates,

a performance of another set of treated and untreated socks was determined as follows:

In accordance with the procedure of Example II, the performance of an untreated sock and a treated sock which had been laundered ten times at 140 F. was determined as follows:

Temperature, F.

Time Bottle 1 Bottle 2- Treated Sock Untreated (after 10 Sock launderings) Example V In accordance with the procedure of Example II, the performance of an untreated sock and another treated sock which had been laundered ten times at 140 F. was determined as follows:

Temperature, F.

Time Bottle 1- Bottle 2- Treated Sock Untreated (after 10 Sock launderings) Example VI In accordance with the procedure of Example 11, the performance of an untreated sock and another treated sock which had been laundered ten times at 140 F. was

determined as follows:

Temperature, F.

Time Bottle 1- Bottle 2- TroatedSock Untreated (after 10 Sock launderings) Start. 2 Min 04. 2s 64. 2o 4 M n 64. 75 06. 25 5 Min 60. 00 67. 00 7 Min- 67.00 68. 25 10 Min 68. 00 70.00 12 14in 68. 75 70. 50 15 Min 70. 25 72. 50 17 171111 71.00 73.00 20 Min 72. 00 74. 75 Min 72. 75 77. 0O Min 75.00 80. 45 Min 76. 25 86. 25 lylin 78. 00 92. 50 hiin 80. 25 101.00 IVIin 86. 75 110. 25

As the above examples indicate, dampened socks, treated in accordance with the process of this invention exhibit a greater heat transfer rate than dampened socks which have not been treated in accordance with said process. The effect of this phenomenon in actual use is that persons Wearing cotton clothing such as socks, underwear, etc., close to their skin, are made to feel more comfortable by reason of the higher heat transfer rate through such clothing upon the advent of perspiration. Where no perspiration occurs, the greater heat transfer rate is not noticed, and therefore, super-cooling is not effected.

While the preferred embodiment of this invention has been described in some detail, it will be obvious to one skilled in the art that various modifications may be made without departing from the invention as hereinafter claimed.

Having thus described our invention, we claim:

1. The method of treating cotton fabric, whereupon the treated fabric when moist has a greater heat transfer coefficient than that of moist untreated fabric, comprising the steps of (1) establishing an aqueous solution containing a caustic alkali in an amount within the range of from .25 to 10% by weight of the fabric to be treated,

(2) adjusting the pH of the aqueous solution to within the range of from pH 5.8 to pH 7 by the addition of acetic acid,

(3) immersing the fabric in said solution,

(4) withdrawing the fabric from said solution after liquid takeup thereof to an extent in the range of from 10% to 60% by weight of said fabric, and

(5) then drying the fabric.

2. The method of claim 1 wherein said solution is maintained at a temperature of about F. during said liquid takeup.

References Cited in the file of this patent UNITED STATES PATENTS 693,653 Kertesz Feb. 18, 1902 1,722,171 Bassett July 23, 1929 1,726,142 De Wolf Aug. 27, 1929 2,346,126 Lessig Apr. 11, 1944 3,012,844 Screnock Dec. 12, 1961 OTHER REFERENCES Handbook of Chemistry and Physics, 38th edition, Chemical Rubber Publishing Co., p. 1709. 

1. THE METHOD OF TREATING COTTON FABRIC, WHEREUPON THE TREATED FABRIC WHEN MOIST HAS A GREATER HEAT TRANSFER COEFFICIENT THAN THAT OF MOIST UNTREATED FABRIC, COMPRISING THE STEPS OF (1) ESTABLISHING AN AQUEOUS SOLUTION CONTAINING A CAUSTIC ALKALI IN AN AMOUNT WITHIN THE RANGE OF FROM .25% TO 10% BY WEIGHT OF THE FABRIC TO BE TREATED, (2) ADJUSTING THE PH OF THE AQUEOUS SOLUTION TO WITHIN THE RANGE OF FROM PH 5.8 TO PH 7 BY THE ADDITION OF ACETIC ACID, (3) IMMERSING THE FABRIC IN SAID SOLUTION, (4) WITHDRAWING THE FABRIC FROM SAID SOLUTION AFTER LIQUID TAKEUP THEREOF TO AN EXTENT IN THE RANGE OF FROM 10% TO 60% BY WEIGHT OF SAID FABRIC, AND (5) THEN DRYING THE FABRIC. 